In the manufacture of various components of a nuclear and aerospace industries, it is often necessary to form a eutectic layer on a zirconium or titanium alloy part. In the past, a suitable eutectic layer has been formed by initially forming a film of beryllium on the substrate by vapour deposition of beryllium on the surface of the zirconium or titanium alloy substrate in a vacuum furnace. The coated substrate is then heated in a preselected atmosphere to cause the formation of a eutectic layer with the surface layer of the substrate. The surface of the zirconium or titanium must be scrupulously cleaned beforehand to yield the production of an acceptable eutectic layer.
Because of the extreme toxicity of beryllium vapour, the avoidance of the vapour deposition step in the production of the eutectic layer is most attractive to the industry.
Therefore, it is an object of this invention to produce an acceptable layer of a zirconium-beryllium eutectic on a zirconium alloy substrate or a titanium-beryllium eutectic on a titanium alloy substrate, in the absence of the production of a beryllium vapour.
It is the object of this invention to produce a zirconium-beryllium eutectic layer on the surface of a zirconium alloy part or a titanium-beryllium eutectic layer on the surface of a titanium alloy part without prior extreme surface preparation of the zirconium or titanium alloy substrate.
Before proceeding further, it will be found that this invention will describe the formation of a zirconium-beryllium eutectic on a zirconium alloy substrate. The process applies equally well to the formation of a titanium-beryllium eutectic on a titanium alloy substrate. The description will describe only the production of the zirconium-beryllium eutectic, it being understood that the process applies equally well to the production of the titanium-beryllium eutectic.
It is another object of this invention to produce a zirconium-beryllium eutectic layer on a zirconium alloy substrate, the depth of which may be controlled to very precise limits by controlling the temperature and time the components are in the heated condition.
It is another object of this invention to permit the use of a bar or strip of beryllium in the production of the zirconium-beryllium eutectic layer instead of more costly forms of beryllium required for some types of eutectic production.
It is another object of this invention to produce an acceptable zirconium-beryllium layer on a zirconium alloy substrate where virtually all the beryllium which leaves the donor beryllium element ends up in the eutectic beryllium-zirconium layer and not on the associated equipment used in the enclosure and the associated heating equipment.
It is another object of this invention to avoid the use of sophisticated equipment associated with prior art production methods, and the associated complex control apparatus used to produce an acceptable eutectic layer.
It is an object to produce a zirconium-beryllium eutectic layer on a zirconium alloy substrate in a very efficient economical manner.
It is another object of this invention to avoid the costly waste handling processes associated with previous methods of formation of layers of zirconium-beryllium eutectics.